Is there any way to make the field "Type" (of File) Display the file type icon instead of the long text description. Or, to create a custom field to do this.
You mean the Type column? You could replace the Type column by the Ext column:
Right click the column > more > remove the Type column and add the Extension Column
You can't edit the columns or add custom columns.
If you just want to sort by type you don't need an extra column at all. Instead, hold shift and click the Name column to sort by file extensions.